Nationals of certain countries which are regarded as majority English-speaking countries do not need to to satisfy the English language requirement for naturalisation and do not need to show a formal speaking and listening qualification.

The following countries are regarded as majority English speakers:
  • Antigua and Barbuda
  • Australia
  • The Bahamas
  • Barbados
  • Belize
  • Canada
  • Dominica
  • Grenada
  • Guyana
  • Jamaica
  • New Zealand
  • Republic of Ireland
  • St Kitts and Nevis
  • St Lucia
  • St Vincent and the Grenadines
  • Trinidad and Tobago
  • United States of America.
If you are a dual national and apply with another passport (i.e. your EU/EEA passport), you will need to submit a copy of your valid passport from any of the above countries to prove you satisfy the language requirement. For example, if you have dual US/Italian citizenship and apply as an Italian national, you will also need to submit your US passport.

If you are not able to provide a valid passport for this purpose, you will need to provide a current national identity document or an original letter from you government or embassy confirming your full name, date of birth and nationality

The Life in the UK test is still required by nationals of majority English-speaking countries.
Source: Pages 18-19 of the Knowledge of language and life in the UK